Chapter 20: Nutritional Application of Vitamins to Human and Animal Health • Chapter overview: – Chapter 20 presents the impacts of vitamins on animal health: • identification and sources of the vitamins • functions of the vitamins • impacts of vitamin deficiencies
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Chapter 20: Nutritional Application of Vitamins to Human and Animal Health Chapter overview: –Chapter 20 presents the impacts of vitamins on animal health:
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Chapter 20: Nutritional Application of Vitamins to Human and Animal
Health
• Chapter overview:– Chapter 20 presents the impacts of vitamins on
animal health:• identification and sources of the vitamins
• functions of the vitamins
• impacts of vitamin deficiencies
Historical Perspective:
• Funk (1912) - introduced the term vitamine, meaning “vital amine”
• Later the word vitamin was adopted, also referring to the latin term vita for “life”
Vitamin Definition:
• Organic compounds essential for normal growth and maintenance of life– Required only in minute amounts– Do not contribute energy, but some are critical to
metabolism of energy– Some are metabolic, but not dietary, essentials
due to synthesis in the body– Although some are chemically similar to each
other, there is no common chemistry of vitamins
Vitamin Nomenclature:
• Vitamins were originally categorized as:– Fat soluble: extractable with lipid solvents
• vitamins A, D, E, K
– Water soluble: extractable in water solution• vitamin C and the B-complex group
Vitamin A:
• Functions - regeneration of visual purple, essential for normal epithelial tissue
• Deficiency symptoms - night blindness, keratinization of epithelium, xeropthalmia
• Major sources - yellow corn, alfalfa, liver, fish liver oils
• Precursor - carotene
Vitamin D:
• Functions - calcium and phosphorus absorption and metabolism
• Functions - lipotropic action in rat diets in which other vitamins are deficient
• Deficiency symptoms - alopecia
• Major sources - phytin in plant products
Related: Para-aminobenzoic Acid
• Functions - growth stimulant in chicks; anti-gray hair factor in rodents
• Deficiency symptoms - graying hair in animals other than humans
• Major sources - a synthetic product
Vitamin Expression:
• Vitamin potency is expressed in two ways:– Activity: International Units (IU) are the units
of expression, defined as the activity created (example: growth) by a particular amount of a vitamin. Example: 0.3 micrograms of crystalline vitamin A alcohol = 1 IU
– Weight: most B-complex vitamins are reported in supplements by weight. Example: niacin reported as 5mg/lb of a feedstuff
Vitamin Assays:
• Biological assay- feeding known amounts of vitamins to vitamin-depleted animals and assessing performance
• Microbiological assay - using microbes as test subjects in a biological assay method
• Chemical assay - determination of concentration based upon analysis for specific chemical characteristics